Index: src/wp-admin/includes/class-wp-links-list-table.php
===================================================================
--- src/wp-admin/includes/class-wp-links-list-table.php	(revision 26339)
+++ src/wp-admin/includes/class-wp-links-list-table.php	(working copy)
@@ -175,6 +175,14 @@
 	 					?><td <?php echo $attributes ?>><?php echo $rating; ?></td><?php
 						break;
 					default:
+						/**
+						 * Fires for each registered custom link column.
+						 *
+						 * @since 2.1.0
+						 *
+						 * @param string $column_name Name of the custom column.
+						 * @param int    $link_id     Link ID.
+						 */
 						?>
 						<td <?php echo $attributes ?>><?php do_action( 'manage_link_custom_column', $column_name, $link->link_id ); ?></td>
 						<?php